Endovascular flexible stapling device

ABSTRACT

The present invention concerns a flexible stapling device ( 1 ). More particularly, this invention concerns a flexible endovascular stapling device ( 1 ) for an intravascular procedure such as patent foramen ovale closure, which is designed to avoid open heart surgery by permitting the closure of the defect utilizing a stapling means ( 26 ) which is positioned by using a flexible shaft/guidewire system.

This application claims benefit of provisional application Ser. No.60/024,640 filed Aug. 22, 1996.

FIELD OF THE INVENTION

The present invention relates to a flexible stapling device. Moreparticularly, this invention relates to a flexible endovascular staplingdevice useful for intravascular procedures such as patent foramen ovaleclosure, atrial septal defect closure, valve repair, or valvereplacement, which is designed to avoid open heart surgery by permittingthe closure of the defect and/or valve repair or replacement utilizing astapling means which is positioned by using a flexible shaft/guide wiresystem or by direct vision.

BACKGROUND OF THE INVENTION

Cryptogenic strokes potentially account for 40% of the 500,000 strokeswhich occur in the United States each year. Many of these events may beassociated with a patent foramen ovale (small atrial septal defect)which permits debris in the venous circulation to cross over into thearterial circulation where it may travel to the brain. Treatment forthese patients often includes open heart surgery to close the defect.

A number of prior art references are known:

U.S. Pat. No. 4,473,077, which issued to Noiles et al on Sep. 25, 1984,discloses a flexible shafted surgical stapler generally useful foranastomosis procedures;

U.S. Pat. No. 4,485,817, which issued to Swiggett on Dec. 4, 1984,teaches a stapler with flexible shaft construction having hydraulictransmission/drive means. This stapler is used primarily for anastomosisof hollow body vessels; and U.S. Pat. No. 5,042,707, which issued toTaheri on Aug. 27, 1991, relates to an articulated stapler for use inthe vascular system.

However, none of the above references teaches the use of a flexiblestapler for intravascular procedures such as patent foramen ovaleclosure or a flexible stapler suitable for these procedures.

OBJECTS OF THE INVENTION

It is an object of the invention to provide an endovascular flexiblestapling device.

It is also an object of the invention to provide an endovascularflexible stapling device useful for closure of a patent foramen ovaledefect, atrial or ventricular septal defect closure, valve repair, orvalve replacement, without the need for open heart surgery.

It is a further object of the invention to provide a method ofperforming intravascular procedures whereby a endovascular flexiblestapling device is inserted into a body.

It is a yet further object of the invention to provide for a method ofclosing a patent foramen ovale defect, atrial or ventricular septaldefect closure, valve repair, or valve replacement, without the need foropen heart surgery.

These and other objects of the invention will become apparent from thefollowing discussion of the invention.

SUMMARY OF THE INVENTION

The present invention provides for a endovascular flexible staplingdevice. More particularly, this invention provides for a flexibleendovascular stapling device for a procedure such as patent foramenovale closure, which is designed to avoid open heart surgery bypermitting the closure of the defect utilizing a stapling means which ispositioned by using a flexible shaft/guide wire system introduced viathe femoral vein or the jugular vein. One application for the flexiblestapling device of the present invention is to pass the device via afemoral vein into the right atrium of the heart and, with the guidanceof transesophageal echocardiography, position the device, and then fireone or more staples to obtain closure of the defect.

The construction and obvious advantages of the system provided for bythe present invention will be more clearly understood from the followingdescription of the various specific embodiments when read in conjunctionwith the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a longitudinal, partly cross-sectional view of the flexiblestapling device of the present invention;

FIG. 1(a) is an end view of the flexible stapling device of FIG. 1showing in cross-section the position of the staples prior to use foreffecting closure of a defect;

FIG. 1(b) is a lateral view of a typical staple which is incorporatedinto the distal end of the device of FIG. 1;

FIG. 1(c) is a cross-sectional view of the distal end of the device ofFIG. 1(a), showing a staple in a closed position;

FIG. 2 is a longitudinal view of the introducer element used forinsertion of the flexible stapling device;

FIG. 3 is a longitudinal view of the guidewire upon which the flexiblestapling device of the present invention glides to position the devicein proximity to the defect to be closed;

FIG. 4 is a longitudinal view of a typical dilator which is used forgradually increasing the size of a vein to permit the easy introductionof the flexible stapling device of the present invention; and

FIG. 5 is a perspective view of a staple useful according to theinvention.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is directed to an endovascular flexible staplingdevice. More particularly, this invention relates to a transfemoralflexible stapling device useful for a number of intravascularprocedures. For example, the flexible stapling device can be used forpatent foramen ovale closure which is designed to avoid open heartsurgery by permitting the closure of the defect utilizing a staplingmeans which is positioned by using a flexible shaft/guide wire system.However, the device can also be used for atrial or ventricular septaldefect closure or valve repair or replacement by an endovascular routeor by direct vision.

As noted above, many of the cryptogenic strokes which occur in theUnited States each year can be associated with the existence of thesmall atrial septal defects known as patent foramen ovale defects.Historically the primary treatment used for patients who may have beendiagnosed with such defects has been medical therapy with anticoagulantsor anti-platelet agents, or open heart surgery to repair the septaldefect.

The device of the present invention is designed to avoid open heartsurgery by allowing for the closure of the septal defect utilizing aflexible shaft device which incorporates a stapling means. This devicemay be introduced by a femoral vein into the right atrium of thepatient's heart where, with the guidance of transesophagealechocardiography, the device may be positioned and staples may be fired.

The invention can perhaps be better appreciated by making reference tothe drawings. With reference to FIG. 1 a longitudinal, partlycross-sectional view of the flexible stapling device 1 of the presentinvention is shown, wherein the essential components are depicted. Aflexible catheter shaft 10 is shown which incorporates at the proximalend 11 multiple hand grips 12 for maneuvering the device 1 into apatient's vein and properly locating the distal end 14 in proximity tothe defect to be closed. Distal to the hand grips 12 is a guidewire port16, through which passes the proximal end of a guidewire 18 over whichthe flexible stapling device 1 slides and is guided into position.Guidewire port 16 could optionally be located elsewhere, for example, atthe proximal portion 17 of hand grips 12.

Distal to guidewire port 16 is a slide mechanism 20 for retracting aretractable external housing 22, located at the distal end 14 offlexible shaft 10. Slide mechanism 20 is operatively connected bysuitable actuation means 24 to retractable external housing 22 tofacilitate retraction of the housing 22 once the distal end 14 of thedevice 1 has been properly positioned in proximity to the defect to beclosed. Retractable housing 22 could comprise a cylindrical memberhaving an inner diameter slightly greater then the outer diameter ofshaft 10.

Located within retractable housing 22 are one or more, preferably 2 or4, barbed staples 26 which have been properly positioned to presentintimate contact between the barbed tips 28 of the staples 26 and theportion of the patient's septum to be closed once external housing 22has been retracted.

FIG. 1a is a cross-sectional view of the distal end of the flexibledevice 1 of FIG. 1 showing four separate barbed staples 26 releasablypositioned on a staple holding member 27 within external housing 22.Each of the staples 26 has been preformed and has barbed ends 28 forinsertion into the septum wall presenting the defect. Holding member 27for the staples 26 has a guidewire exit port 30 through which theguidewire 18 extends distally from the flexible shaft 10 of the device.

An actuator such as handgrips 12 or, optionally, an actuator 15, isoperatively connected to holding member 27 and/or staple closer 25, sothat staples 26 are simultaneously closed and released when thehandgrips 12 are squeezed together or actuator 15 is activated. Theoperative connection can be mechanical, electrical, or other. Afterdischarge of staples 26, holding member 27 could be either re-fittedwith new staples 26 or replaced with a replacement holding member 27with staples already in place, e.g., a “clip”.

In FIG. 1b a typical barbed staple 26 is depicted showing the angularpreformed configuration of the staple 26. The barbed tips 28 allow forthe insertion of the staples to effect closure of the defect withoutallowing them to spontaneously release from the wall in which they havebeen inserted.

FIG. 1(c) represents the distal end of flexible device 1 where externalhousing 22 has been retracted and staple 26 has been closed. Barbed ends28 of staple 26 are in a closed, almost touching position. In oneembodiment of the invention, staple closer 25 moves distally relative toholding member 27 to cause barbed ends 28 to close on the intendedtarget tissue or organ, such as the septum. Optionally, other mechanismsthat can be activated proximally, are operatively connected to a distalstaple holding member, and cause the staples to close on an intendedtarget could be used in place of the system described here. Also, it iscontemplated that the device 1 could optionally comprise fiber opticsand/or light or imaging transmitting means, as well as one or moreworking channels or lumens.

With reference to FIG. 2, a longitudinal view of an introducer element40 of the system of the present invention is depicted. A one way-valve42 is located at the proximal end 41 of the introducer element 40 and agenerally circular opening 44 is located at the distal end thereof.

FIG. 3 depicts a perspective view of the guidewire 50 showing a curvedtip 52 at the distal end thereof.

FIG. 4 depicts a perspective view of a typical dilator 60, which can bea set of 2 or more progressively larger dilators for gradual dilation ofa vein or artery. The last dilator passes first through introducer 40and then into, for example, a vein. In a set of three dilators, thelengths could be 20 cm, 20 cm, and 55 cm. An orifice 62 is located atthe proximal end of dilator 60 for passage of the guidewire. A taperedtip 64 is located near the distal end thereof, and a generally circularopening 66 is located at the distal end.

It is contemplated that the flexible shaft of the stapling device of thepresent invention may be effectively constructed of a suitablewire-reinforced polymeric material. Preferably the material chosenshould allow for the easy curvature of the shaft of the device withoutthe need for excessive forces being applied, while at the same timeproviding for the necessary overall rigidity to the shaft to allow forthe insertion of the device in the patient's vein.

In overall length the flexible stapling device depicted in FIG. 1 willbe approximately 110 cm. Shorter or longer overall lengths are alsocontemplated as may be required to effect a particular procedure.

The overall diameter of the cross-section of the flexible shaft 10 ofthe device 1 depicted in FIG. 1 is approximately 5 mm. It iscontemplated that similar devices may be constructed having overalldiameters of the flexible shaft which vary somewhat to accommodate thedifferent size veins into which the device must be inserted. Therefore,shaft diameters could range from about 5 to about 15 mm.

The retractable external housing 22 at the distal end of the device 1will have an overall diameter of approximately 5.5 mm to 16 mm. Again,variations in this diameter are contemplated depending upon the needs ofa particular procedure and to accommodate patients having unduly smallveins.

The barbed staples which are located at the distal end of the staplerdevice will have an overall length of approximately 4 mm to 14 mm.Again, the precise configuration of the staple, the actual dimensions ofthe barbs as well as the overall size of the staple itself, arevariables which will be determined by the conditions which prevail incarrying out any particular procedure and the physiological requirementsof the patient involved.

The number and actual location of staples within the retractableexternal housing 22 may also vary depending upon the needs of aparticular procedure.

In an optional embodiment of the invention shown in FIG. 5, each staple70 may have a filament 72 extending from staple 70 a sufficient lengththat the proximal end of each filament would extend outside thepatient's body. Then, if staple 70 were not positioned properly, thesurgeon could retrieve staple 70 by pulling firmly on filament 72. Ifstaple 70 is properly positioned, filament 72 would merely be cut. It iscontemplated that a length of from about 20 to 100 cm of filament 72would be fixedly attached to each staple 70. The filaments 72 could becomprised of any flexible, physiologically acceptable natural ormanufactured material, such as acetates or polyacetates, etc., used insutures. The distal end of each filament 72 would be glued or physicallyaffixed to each staple 70.

With regard to the introducer element depicted in FIG. 2 it is generallycontemplated that the overall length of this element, taken from thebase of the one-way valve located at the proximal end thereof to thedistal tip of the element, will be from about 30 to 60 cm, preferablyapproximately 50 cm. The overall diameter of the introducer element atthe distal end will be from about 6 mm to 20 mm, or as initiallydepicted approximately 6.7 mm, to accommodate the passage of theflexible shaft stapling device through the opening provided.

The guidewire which is depicted in FIG. 3 will have an overall length ofat least from about 90 to 130 cm, preferably 110 cm, to properlyfunction with the flexible shaft stapling device depicted in FIG. 1. Theoverall diameter of the guidewire will generally be from about 0.30 to0.50 mm, preferably about 0.38 mm, although variations in the actualdiameter of the guidewire are contemplated.

The dilator depicted in FIG. 4 is typical of a series of three or moredilators which vary in length from about 20 to 55 cm.

The overall diameter of the largest cross-section of each dilator willbe no more than the opening provided at the distal end of the introducerelement. It is, therefore, contemplated that the overall diameter of thedilators will be from about 5 to 15 mm.

In the method of the invention one or more of the smaller diameterdilators is inserted into a femoral vein to permit gradual enlargementof the patient's vein using successively larger diameter dilators andultimately to allow entry of the introducer element. The largest in theseries of dilators used will be inserted first through the introducerelement and then into the vein which had been previously enlarged usingsmaller diameter dilators.

After the introducer element has been properly positioned within thepatient's vein, and the guidewire positioned through the defect, aflexible stapling device according to the invention is then insertedthrough the introducer over the guidewire and with the aid oftrans-esophageal echocardigraphy or other similar procedure, the distalend of the flexible stapler device is positioned adjacent or near to thepatent foramen ovale requiring closure. The staples are then propelledor fired by retracting the external housing utilizing the slidemechanism provided in the proximal end of the flexible stapler shaft.

While, as described above, the flexible stapling device of the inventionis useful for patent foramen ovale closure, there are otherintravascular procedures for which the flexible stapling device can beused. Such procedures include, for example, the correction of atrialseptal or ventricle septal defect, closure of paravalvular leaks, orannuloplasty repair of valvular insufficiency or valve replacement.

Also, the flexible stapling device need not be inserted percutaneously.In certain applications a cut down procedure at the leg can be employedwith direct vision of the procedure or with the heart open duringminimally invasive surgery. In addition, multiple sizes of the flexiblestapling device should be available.

It will be further apparent to one skilled in this art that theimprovements provided for in the present invention, while described withrelation to certain specific physical embodiments also lend themselvesto being applied in other physical arrangements not specificallyprovided for herein, which are nonetheless within the spirit and scopeof the invention taught here.

We claim:
 1. A system for endovascular closure comprising: a generallyelongated introducer element having a proximal end and a distal end,having at the proximal end thereof a one way valve and having at thedistal end thereof a generally circular opening; an elongated guidewirehaving a curved tip at the distal end thereof; one or morelongitudinally-extending dilators of varying diameters each having aproximal end and a distal end, each having at the proximal end thereofan orifice, and each having at the distal end thereof a tapered tipculminating in a generally circular opening for guidewire passage; andan elongated flexible shaft stapling device having proximal and distalends, an actuator located at the proximal end of said flexible shaft, aguidewire entry port located at the proximal end of said flexible shaft,a guidewire exit port located at the distal end of said flexible shaft,one or more staples releasably positioned on a holding member at thedistal end said flexible shaft, and a stapler closer operativelyconnected to the actuator for closing the staples, wherein activation ofthe actuator causes the one or more staples to close and separate fromthe holding member.
 2. The system according to claim 1, wherein thegenerally elongated introducer element has a length of approximately 50cm.
 3. The system according to claim 1, wherein the generally elongatedintroducer element has an overall diameter of from about 6 to 20 mm. 4.The system according to claim 1, wherein the guide wire has an overalldiameter of approximately 0.38 mm.
 5. The system according to claim 1,wherein each dilator has an overall length of from about 20 cm to about55 cm.
 6. The system according to claim 1, wherein the overall diameterof the largest cross-section of each dilator is from about 5 to about 15mm.
 7. The system according to claim 1 for effecting closure of a patentforamen ovale defect, atrial or ventricular septal defect closure, valverepair, or valve replacement, without the need for open heart surgery.8. The system according to claim 1 that is useful during minimallyinvasive open heart surgery and under direct vision.
 9. A method ofeffecting intravascular closure comprising: (a) advancing a guidewirepercutaneously or by incision using Seldinger technique into a patient'svein; (b) advancing one or more dilators successively over a guidewireinto the proximal end of the femoral vein and distally into thepatient's femoral vein to permit gradual enlargement; (c) advancing theintroducer over the guidewire where the introducer has distal andproximal ends and the proximal end of the introducer remains outside thepatient's body; (d) advancing a guidewire through the introducer anddistally to a position through the defect in the patient's heart septumor other appropriate location; (e) advancing a flexible stapling devicehaving distal and proximal ends, where said distal end comprises staplesand a retractable external housing and the proximal end comprisesactuating means to retract the housing and to cause the staples to befired; (f) positioning the distal end of the flexible shaft staplingdevice in proximity to the defect; and (g) activating the mechanism toeffect the positioning of the staples located at the distal end of theflexible shaft; and (h) withdrawing the flexible stapling device andthen the introducer from the patient's vein.
 10. The method of claim 9,wherein transesophageal echocardiography is used to position theguidewire distal tip and/or the distal tip of the stapler device. 11.The method of claim 9, wherein a patent foramen ovale is closed.
 12. Themethod of claim 9, wherein a atrial septal defect or a ventricle septaldefect is closed or treated.
 13. The method of claim 9, wherein aparavalvular leak is closed.
 14. The method of claim 9, wherein valvularinsufficiency is repaired, or valvular stenoses are repaired or replacedwith prosthetic material/devices.